diff --git a/glamor/glamor.c b/glamor/glamor.c
index c398807f1..358890375 100644
--- a/glamor/glamor.c
+++ b/glamor/glamor.c
@@ -316,7 +316,7 @@ glamor_init(ScreenPtr screen, unsigned int flags)
 {
     glamor_screen_private *glamor_priv;
     int gl_version;
-    int max_viewport_size;
+    int max_viewport_size[2];
 
 #ifdef RENDER
     PictureScreenPtr ps = GetPictureScreenIfSet(screen);
@@ -408,8 +408,9 @@ glamor_init(ScreenPtr screen, unsigned int flags)
     glamor_priv->has_buffer_storage =
         epoxy_has_gl_extension("GL_ARB_buffer_storage");
     glGetIntegerv(GL_MAX_TEXTURE_SIZE, &glamor_priv->max_fbo_size);
-    glGetIntegerv(GL_MAX_VIEWPORT_DIMS, &max_viewport_size);
-    glamor_priv->max_fbo_size = MIN(glamor_priv->max_fbo_size, max_viewport_size);
+    glGetIntegerv(GL_MAX_VIEWPORT_DIMS, max_viewport_size);
+    glamor_priv->max_fbo_size = MIN(glamor_priv->max_fbo_size, max_viewport_size[0]);
+    glamor_priv->max_fbo_size = MIN(glamor_priv->max_fbo_size, max_viewport_size[1]);
 #ifdef MAX_FBO_SIZE
     glamor_priv->max_fbo_size = MAX_FBO_SIZE;
 #endif